This invention relates generally to driving tools and, more particularly, to a magnetically operated driving tool that does not require electric energy.
Driving fasteners such as nails, rivets, or staples is one of the most important tasks a tool can accomplish. The nail-gun, more than any other tool, is responsible for the accelerating pace and profitability of house building. Recently, many “in home” and cordless versions of tools have appeared. These devices are smaller and lighter than their industrial counterparts, yet they perform the same functions.
Various devices utilizing magnetic force as a method for propulsion have been proposed in the art. Solenoids use this force directly, as do all electric motors. In both of these cases, however, at least one of the magnets is an electric magnet. Examples of devices that use electricity with magnets for propulsion can be found in U.S. Pat. No. 3,899,703 and U.S. Pat. No. 6,232,689.
Similarly, using magnetic force to power a nail-gun is known in the art, such as in U.S. Pat. No. 4,183,453, U.S. Pat. No. 4,611,742, and U.S. Pat. No. 6,364,193. However, these devices all require an electric power source. This means that they must be corded, making them cumbersome to use and reducing their mobility, or battery operated. Batteries only provide power for a limited time, are expensive, and can leak, which causes safety concerns and can potentially ruin the tools.
Other devices are known that use magnetic force for propulsion without electricity, such as in U.S. Pat. No. 3,609,425 and U.S. Pat. No. 6,433,452, but these devices are ill suited for driving tools. U.S. Pat. No. 3,609,425 requires driven magnets that selectively intercept the established magnetic fields and drive a reciprocating magnet to its alternate position; these driven magnets would make a hand-held driving tool bulky and cumbersome to use, and it is unclear that this device would supply sufficient instantaneous force to drive a fastener. U.S. Pat. No. 6,433,452 does not deliver a single burst of propulsion as is needed for a driving tool; instead, a rotatable balance wheel rotates continuously to maintain rotation of an output shaft.
Therefore, it is desirable to have a magnetically operated driving tool that provides sufficient instantaneous force to drive a fastener, does not require electric energy, is light, compact, and easy to use, and can be easily manufactured.